Metallic rod-packing.



G. L. TRAP? & 0. G. GEHRMAN.

METALLIC BOD PACKING.

APPLICATION FILED SEPT. 1, 190a.

Patented July 26, 1910.

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UNITED srnrns near one CHARLES L. TRAPP, OF SOUTH OMAHA, AND OTTO G.GEHRMAN, OF OMAHA, NEBRASKA, ASSIGNORS OF ONE-FOURTH TO FRANK J. MEYERS,OF OMAHA, NEBRASKA.

METALLIC ROD-PACKING.

- Application filed September 1, 1908.

Specification of Letters Patent.

T 0 all whom it may concern:

Be it known that we, CHARLES L. TRAPP and O'r'ro O. GEHRMAN, citizens ofthe United States, and residents, respectively, of South Omaha andOmaha, in the county of Douglas and State of Nebraska, have inventedcertain new and useful Improvements in Metallic Rod-Packing, of whichthe following is a specification.

Our invention relates to metallic rodpacking and it is the objectthereof to provide a. packing of this class especially adapted for useon ammonia compressors.

With this object in view, our invention consists, first, in theconstruction of the packing rings of which the segmentation is such thata single ring is sufficient to prevent leakage under ordinaryconditions, and sec- 0nd, in the arrangement of the packing within ahousing in such a manner that, of the two sets of packing employed, oneof the same is not subjected to a pressure greater than the backpressure on the compressor, which in ordinary practice does not exceedthirty pounds per square inch.

Constructions embodying our invention are shown in the accompanyingdrawings in which Figure 1 is a sectional View of the packing, thesection being taken longitudinally of the rod, Fig. 2 is an endelevation of one of the packing rings, and Fig. 3 is a side elevation ofthe same.

In carrying out our invention we provide two sets of packing which arearranged serially upon the rod 1 within the stufiingbox' 2. The two setsof packing are inclosed within a housing which forms an outer and aninner compartment so that each set of packing is entirely separate fromthe other. The housing for the inner set of packing, or that nearest thecylinder, is formed by the rings 3 and 4 and the sleeve 5. The housingfor the outer set of packing is formed by the rings 4 and 6 and thesleeve 7. Between the ring 3 and the bottom of the stuflingbox, and ateach end of the sleeves 5 and 7 between the same and the rings 3, 4 and6, are placed soft-metal gasket-rings 8. The outer ring 6 is engaged bythe gland 9 and, by means of the nuts 10 working on the studs 11, saidgland is forced into engagement with said ring 6. The various members ofthe housing are thus pressed into engagement with the gasket-rings 8 sothat gas-tight joints are formed thereby and the gas which escapes fromthe cylinder around the rod is confined within the housing.

Each set of packing consists of one or more packing rings 12, an annularcoil spring 13 encircling each packing ring, a followerring 14, and afacing-ring 15. The follower rings 14 are pressed yieldingly against thepacking rings by means of coil springs 16 disposed in recesses in thehousing-rings 3 and 4, as shown. The front portions 17 of thefacing-rings 15, adjoining the rings 4 and 6, are formed of soft metalsuch as babbitt which is cast into dovetail grooves in the faces of therings, as indicated.

The segmentation of the packing rings will be apparent from the Figs. 2and 3. Each ring is divided int-o three or more like segments, theabutting end-faces of which are shouldered or offset transversely oftherod, the two portions of each face lying in parallel planes tangent tocylinders concentric with the rod and of a diameter not greater thanthat of the rod. The segments 'are held to the rod by the annular coilsprings 13 which are retained in grooves formed in the peripheries ofthe rings, and said springs together with the pressure of the gas uponthe segments force them in upon the rod to compensate wear. The movementof the segments in closing upon the rod will be apparent by reference tothe dotted positions thereof in Fig. 2.

Referring to Fig. 1 it will be seen that the gas from the cylinder hasfree access to the inner compartment of the housing inside of the sleeve5, but is prevented from reaching the outer compartment of the housingexcept by leakage through the inner set of packing. Should any of thegas leak through the inner set of packing it willenter the outercompartment of the housing and be prevented from further escape by theouter set of packing. In order that the pressure in the outercompartment of the housing may not be greater than the back pressure ofthe compressor, a cheek-valve is arranged in the ring 4 between theouter and inner compartments, said valve consisting of a ball 18arranged in an inclined passage through the ring 4, said ball normallyresting on a valve seat and being held thereon by a small coil spring19. The valve being openable toward the inner compartment of thehousing, whenever the pressure in the outer compartment becomes greaterthan the back pressure of the compressor the valve will be opened at thesuction stroke of the compressor and the gas return through the passageto the inner compartment, the valve closing when the pressures haveequalized.

Now, having described our invention, what we claim and desire to secureby Let ters Patent is:

1. In a metallic rod-packing, a housing surrounding the rod and havingtwo packing compartments formed therein, a set of packing arranged ineach compartment of the housing, there being a passage connecting theouter compartment with the inner, and a check-valve in said passagearranged to open toward the inner compartment.

2. In a metallic rod-packing, a packing ring consisting of a. pluralnumber of segments having abutting endsfaces shouldered onlytransversely to the rod, the portions of each face on opposite sides ofthe shoulder lying in planes parallel to each other and tangent tocylinders concentric with the rod and of a diameter slightly less thanthe rod, and means embracing the ring to hold the segments upon the rod.

3. In a metallic rod-packing, a housing surrounding the rod andconsisting of alternate rings and sleeves, the said rings and sleevesbeing arranged to form an inner and an outer packing compartment, a setof packing arranged in each compartment of the housing, there being apassage connect-' ing the compartments, and a Valve arranged in saidpassage.

4. In a metallic rod-packing subjected to variable pressures, a housingconsisting of alternating rings and sleeves arranged serially upon therod, means for removably holding said rings and sleeves in engagementwith each other, there being packing compartments formed in said housingone ofwhich is exposed to the variable pressures, a set of packingarranged in each of said compartments, there being a passage connectingthe compartments, and a valve in said passage, said valve being openableby the pressure in one compartment when the same exceeds the minimumpressure in the compartment exposed to the variable pressures.

5. In a metallic rod-packing, a housing consisting of separable portionssurrounding the rod and forming two packing compartments thereinadjoining the rod, a set of packing arranged in the inner of saidcompartments and exposed directly to variable pressures, a set ofpacking arranged in the outer compartment and exposed only to thepressure of gases leaking through the inner set of packing, there beinga passage connecting the compartments, and a valve controlling the saidpassage whereby when the pressure in the outer compartment exceeds thepressure in the inner compartment the gas in the outer compartment maypass therefrom to the inner compartment.

6. In a metallic rod-packing, a packing ring consisting of a pluralnumber of like segments having abutting end-faces shouldered onlytransversely to the rod, the portions of each face on opposite sides ofthe shoulder lying in planes substantially parallel with each other, thelike portions of each of the end-faces lying in planes tangent to acylinder concentric with the rod and of a diameter slightly less thanthe same, and means for holding the segments upon the rod.

In testimony whereof we have hereunto subscribed our names in thepresence of two witnesses.

CHARLES L. TRAPP. OTTO O. GEHRMAN.

IVitnesses:

D. O. BARNELL, ROY Gr. KRA'rz.

